Ink jet printing of characters such as alphanumeric or bar code types is well known and commonly employs so-called continuous ink jets or impulse type ink jets. A continuous ink jet ejects a fast stream of ink droplets which are controllably deflected to print characters on a sheet. An impulse ink jet ejects ink droplets for printing only in response to individual electrical pulses. In a typical impulse ink jet head a plurality of ink retaining orifices are formed at the front of the head and the droplets are ejected from each orifice depending upon the character to be printed.
The characters printed with an ink jet head are formed of patterns of dots. The dot pattern may be chosen in view of desired font type. Computer control of an ink jet to print characters is well known.